\documentclass[12pt]{article}
 \textheight7cm \textwidth11cm \parindent0mm \parskip 1ex plus2ex minus0.8ex
\begin{document}

\renewcommand{\footnoterule}{\rule{10mm}{0.2mm}\vspace{-0.2mm}}

Footnotes\footnote{And this is the text of the footnote} are numbered%
\footnote{Of course you can influence this!}
automatically.

\section{Footnotes in headings\protect\footnotemark}

\footnotetext{They are possible, of course; this example shows you
how to do it.}
In sectional headings, footnotes must be produced with the aid of
\verb|\footnotemark| and \verb|\footnotetext| and must be protected by
\verb|\protect|.

Animals: \fbox{Gnats\footnotemark\ and elephants\footnotemark}
\addtocounter{footnote}{-1}\footnotetext{Small insects}
\stepcounter{footnote}\footnotetext{Large animals}
\end{document}
